The invention relates generally to the field of wireless telephony and more particularly to the process of handling an incoming call to a mobile station while the mobile station is currently in an access state or a paging state.
In the existing art, wireless telephone networks use a mobile switching center (MSC) to set up incoming and outgoing calls for mobile stations which are currently registered with the MSC. When an MSC sets up an incoming call to a mobile station, the mobile station briefly transitions to a “paging state”, that is, a state in which a base transceiver station (BTS) in the wireless network is in the process of paging the mobile station and/or waiting for a page response message from the mobile station. Similarly, when a mobile station is seeking to gain access to the wireless network to place an outgoing call, a mobile station transitions briefly to an “access state”, that is, a state in which it is exchanging set up messages with the BTS. The period of time during which the mobile station is in the paging state or in the access state may last from anywhere from 5 to 30 seconds, typically.
After being in the access state or the paging state, a mobile station transitions to what is known as a “traffic” state. In the traffic state, a traffic channel is set up between the mobile station and the BTS and a communication path between the MSC and the mobile station exists, allowing for communication between the mobile station and the other party to the call to occur via the MSC, BTS and air interface on the mobile station.
In the current state of the art, if a mobile station is in the access state and an incoming call for the mobile station arrives at the MSC, the MSC will simply send the new incoming call to the mobile station's voice mail. If the mobile station is in the paging state, the incoming caller will get a busy tone. The MSC will not notify the mobile station of the incoming call at the time, since there is no way to do so today while the mobile station is in the paging state or access state. In the case of two basically simultaneous incoming calls (a situation referred to herein as a “paging state scenario”), the mobile station is not aware that the second incoming call exists because it is already in the paging state as a result of the first incoming call. Thus, the user of the mobile station has no opportunity to decide which of the two essentially simultaneous incoming calls to take.
In the case of an incoming call arriving while the mobile station is already in the process of making a new outgoing call (a situation referred to herein as an “access state scenario”), the user of the mobile station will not know of the fact that this new incoming call has occurred because it will be sent to voice mail. The user will not have the opportunity to abort their outgoing call and take the new incoming call instead.
In either the paging state scenario or the access state scenario, had the user of the mobile station known that the other call was coming in, they may have preferred to take that call instead. Indeed, in some situations the fact that the incoming call was occurring and available to take, without going into voice mail, may be critically important to the user of the mobile station. In other situations, it may not be so critically important to the user of the mobile station to take the new incoming call and they may be content to have the call sent to their voice mail. Unfortunately, in the present state of the art, the user does not have the opportunity to make a decision about whether or not to take an incoming call while their phone is already in the access state or the paging state. Rather, they will only know of the existence of this call when they go to check their voice mail.
This invention is directed to methods of correcting this situation. The methods allow users of mobile stations to become aware of, and select, a new incoming call even after they have entered a paging state or an access state, thereby solving the above described problems.